Mobile stations operate in various operating modes, use different technologies, and utilize different protocols as they move across different networks or across the same network. For example, mobile stations may operate according to frequency division multiple access (FDMA) or time division multiple access (TDMA) technologies. In other examples, mobile stations may operate according to full rate or half rate vocoder technologies.
These different modes may determine different operating characteristics of the mobile station. In one example, the operating mode determines whether the mobile station utilizes FDMA or TDMA technologies. Being able to operate the mobile station according to different modes allows the mobile station to operate more efficiently and effectively as it moves across different operational environments.
The bandwidth on a communication channel used to conduct communications between mobile stations and other devices can be divided or structured in a variety of different ways. For example, with TDMA communications, the communication channel bandwidth may be divided into time slots and different communications can be conducted within these time slots.
Unfortunately, situations exist where it is difficult or impossible to efficiently utilize the bandwidth of communication channels. For example, when assigning FDMA communications, the full bandwidth of a channel is required to conduct the communication. Existing wide area communication systems that support bandwidth allocation of TDMA communications to communication channels, such as the Motorola Dimetra IP solution, employ a bandwidth allocation algorithm in which TDMA communication requests are evenly distributed across all communication channels at a site. Consequently, in a mixed FDMA/TDMA system, if TDMA communications are assigned in an even distribution manner across all communication channels at a site, it becomes difficult to support a FDMA communication request since the entire communication channel must be free of communications in order to support the request. Therefore, if communication channels are not assigned efficiently in a mixed FDMA/TDMA system, FDMA communications may not be able to obtain the needed resources (i.e., the entire bandwidth of the communication channel) thus resulting in the FDMA communication being delayed or dropped.
In another example, secure TDMA communications typically require the distribution of call control signaling as well as, for example, encryption synchronization information. When two or more secure TDMA communications are assigned to the same communication channel, a substantial amount of bandwidth is needed for call control and encryption synchronization information. Consequently, when the secure TDMA communication is assigned to the same communication channel as active (on-going) TDMA communications, the amount of signaling information that can be distributed is greatly reduced. Therefore, if multiple TDMA secure communications are active on a communication channel, the amount of call control signaling bandwidth is greatly reduced resulting in reduced system capability.
As a result of these problems, bandwidth is often inefficiently used in current systems. This inefficient use of system resources causes delays with communications as well as other problems that lead to user frustration with current systems.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and/or relative positioning of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. It will further be appreciated that certain actions and/or steps may be described or depicted in a particular order of occurrence while those skilled in the art will understand that such specificity with respect to sequence is not actually required. It will also be understood that the terms and expressions used herein have the ordinary meaning as is accorded to such terms and expressions with respect to their corresponding respective areas of inquiry and study except where specific meanings have otherwise been set forth herein.